Re: Fine tune your MK3 Y axis
So what is currently recommended for both axes
X axis idler: 16 tooth, 3mm bore, integrated bearing
Y axis idler: 16 tooth, 3mm bore, integrated bearing
or
X axis idler: 20 tooth, 3mm bore, integrated bearing
Y axis idler: 16 tooth, 3mm bore, integrated bearing
I looked at 5mm bore idlers with bearings, (5mm is more rigid) but there are no 16T 5mm bore with bearing idlers around, because the 16T idler is too small for the 5mm bore hole with integrated bearing. only 20T 5mm + bearing available.
btw, one should use Shoulder bolts for the bearings, because its not good for a bearing to flop around on a threaded screw.
Re: Fine tune your MK3 Y axis
Do you have a link for the shoulder bolts you mention we should use for the bearings?
Re: Fine tune your MK3 Y axis
Do you have a link for the shoulder bolts you mention we should use for the bearings?
https://www.pololu.com/product/209
https://www.robotdigg.com/product/368/Idler-Pulley-Post-Shoulder-Screw-5mm-or-6mm
Re: Fine tune your MK3 Y axis
I don’t believe shoulder bolts are necessary at all. I also think that the shoulder of the shoulder bolt won’t be able to fit into the bearings of the idlers we use due to tight tolerances. At the these small sizes/loads it’s not as necessary as if it were, say, a 1/2” bore bearing with a heavy load on it.
Re: Fine tune your MK3 Y axis
I don’t believe
No. Shoulder bolts were made especially for this. http://forums.reprap.org/read.php?178,593682,595629
Re: Fine tune your MK3 Y axis
Don't take this as gospel since I don't know the quality control of the bearings used in the idlers, but the standard tolerances on any shoulder bolt will fit into the standard tolerances on the respective size bearing ID.
Shoulder bolts use negative tolerances (i.e. 5mm -.001/-.005) and bearing IDs use positive tolerances (i.e. 5mm +.001/+.005).
Shoulder bolts at basically fancy shafts.
Re: Fine tune your MK3 Y axis
Don't take this as gospel since I don't know the quality control of the bearings used in the idlers, but the standard tolerances on any shoulder bolt will fit into the standard tolerances on the respective size bearing ID.
Shoulder bolts use negative tolerances (i.e. 5mm -.001/-.005) and bearing IDs use positive tolerances (i.e. 5mm +.001/+.005).
Shoulder bolts at basically fancy shafts.
Agreed, that’s where my concern lies, in the bearings we have. Only one way to find out.
Re: Fine tune your MK3 Y axis
Don't take this as gospel since I don't know the quality control of the bearings used in the idlers, but the standard tolerances on any shoulder bolt will fit into the standard tolerances on the respective size bearing ID.
Shoulder bolts use negative tolerances (i.e. 5mm -.001/-.005) and bearing IDs use positive tolerances (i.e. 5mm +.001/+.005).
Shoulder bolts at basically fancy shafts.
Agreed, that’s where my concern lies, in the bearings we have. Only one way to find out.
The main problem, IMO, is they use a single bearing which allows too much play. My printed idlers with dual bearings solved all my issues, still using the M3 screw.
Re: Fine tune your MK3 Y axis
The main problem, IMO, is they use a single bearing which allows too much play. My printed idlers with dual bearings solved all my issues, still using the M3 screw.
Yeah that definitely minimizes and more than likely removes the twisting of the bearing on the shaft. Thread ODs are standard enough as long as you capture the OD in two spots, which is done with the double-bearing.